In Part 1 of our SIP primer, I covered the SIP foundation layers starting from the message structure and ending with the SIP transactions. We saw how phone registrations and proxies could work using ...

I've been clicking around the Flash-enabled VoIP eLearning Tutorial. Authoritative, vividly illustrated, and totally cool. You click, and you see illustrated guides to how VoIP works, how to configure ...

The iptel.org 180+ page SIP tutorial is outstanding. Another overview that is a bit more market-oriented and nearly as long. White paper on the SIP value proposition over telephony, SIP and the new ...

Voice over IP (VoIP) is the descriptor for the technology used to carry digitised voice over an IP data network. VoIP requires two classes of protocols: a signaling protocol such as SIP, H.323 or MGCP ...